The preparation of high surface area catalysts for use in oil refining, gasification of coal, or for other reactions requiring catalytic surfaces, has been a developing field for many years. Catalysts are presently prepared in many different ways. Hydrodesulfurization catalysts, for example, are usually prepared by co-impregnating a suitable support (e.g. alumina) with a salt (e.g. ammonium heptamolybdate) and a promoter (e.g. a nickel or cobalt salt) followed by calcination. The catalysts are then sulfided immediately prior to use. There are several drawbacks and limitations to the catalyst preparation processes which are presently employed, one of which is high cost. Also, the number of active sites per gram of catalyst is generally low, thereby resulting in low catalyst activity.
Another method for making catalysts involves the exfoliation of a layered transition metal dichalcogenide (e.g. molybdenum disulfide) containing an alkali metal. Alkali metals can be introduced into transition metal dichalcogenides in a number of ways. For example, lithium can be introduced or "intercalated" by soaking the layered compound in a solution of n-butyllithium in hexane, as described by M. B. Dines in Materials Research Bulletin, Vol. 10, pages 287-291 (1975) and in U.S. Pat. No. 3,933,688, issued in 1976. Other methods of obtaining a layered compound with alkali metal between the layers are, for example, intercalation of the transition metal dichalcogenide with the alkali metal from solution in liquid ammonia as described by W. Rudorff in Chimia, Vol. 19, page 489 (1965), or by electrointercalation in an electrochemical cell as described by M. S. Whittingham in U.S. Pat. No. 4,009,052, issued 1977, or R. R. Haering, J. A. R. Stiles and K. Brandt in U.S. Pat. No. 4,224,390, issued 1980, or by exposing the layered compound to hot alkali metal vapors as mentioned on page 308 of Intercalated Layered Materials, edited by F. Levy (1979).
U.S. Pat. Nos. 4,299,892, Dines et al., November, 1981, and 4,323,480, Dines et al., April, 1982, are also of interest in this area.